Bergson takes as an example the learning of a verse by rote — i.e., a recitation tending toward non-reflective and mechanical repetition.
The duration of habitual recitation tends toward the regular, and one may compare this kind of memory to practical knowledge or habit.
Bergson takes as his example the remembrance of the lesson of learning the same verse — i.e., a dated fact that cannot be recreated.
Pure memory or remembrance permits the acknowledgment that the lesson has been learned in the past, cannot be repeated, and is not internal to the body.
Descartes's fault lies in defining matter and memory as substances or res, thus not separating them distinctly.
Bergson really does distinguish the spirit from the body, but as opposed to in Descartes's classical philosophy, the distinction resides in the temporal domain, not in the spatial.
Contenting oneself with reacting to an external stimulus means being unconscious of the act; an existence within the sheer presence of the body.
The articulation of time — past, present, future — finds place through the union of spirit and body.